drainage issues

This actually isn't a commercial question... Its a MIL (Mother In Law) question! So please help!

I was just over at their yard, the whole back 10' of the yard is a LAKE. Her yard backs to a neighbours, both are lower at the back than at the front. (creating a big pond come spring basically!) I've been asked to figure out a way to solve this problem, their thoughts were to truck in a whole lot of loam, and raise the level of their yard... I'm thinking more along the lines of a drainage solution...

I'm not a landscape installer, so I dont know much about these issues... Can anyone help? If it matters, their lawn is composed of about 4" of loam, on top of a clay/sand base.

The problems been getting worse over the last few years, to the point where their new 2 years ago, fence (all pressure treated lumber) is about to be replaced... (I hear I've already been volunteered).

If you raise the level of that area where will all of that water run to ??? Also where is it coming from ?? is it just accumulation from rain , or is it running down from someone elses property ??? Maybe a french drian and or a basin of some sort would help, but How much water is it ??? May want to contact a local professional or even your town for some advice on the situation...

But regardless, before you do any work think of where the water will wind up if that dip isnt there anymore, will it wind up in your MIL 's basement or the neighbors ??? That could be a very costly mistake.....

My experience here in the states has been that if you modify the grade and flood-out someone else's yard/home you can be held liable. You need to find out where the water is coming from. Contact the local authorities and see if they can help bring expertice to bear on this problem.

As far as your drainage problems go two thoughts come to my mind. 1) A loam placed on top of a sandy/clay soil causes an abrupt interface between the two soil types. The loam must reach saturation before water will permeate into the sandy/clay soil. This can be a cause of drainage problems. 2) The sandy/clay soil is more clay than sand and acts to prevent water percolation into the subsoil. If number one is your problem you could remove the loam and replace it with a soil that matches the sandy/clay soil. This would eliminate the soil interface, but it is also a very expensive solution and does not fix the second problem (if that is in fact your problem). Another possible aid would be to drill several holes in the lowest spots of that back yard and fill them with gravel to allow the water to infiltrate into the subsoil. Drill deep enough to get to the horizon 'C' subsoil (below the sandy/clay). If this horizon 'C' subsoil is well drained you may help the water drain quicker from your back yard. Good luck.

lawnstudent, i laugh. i can have a falt lawn and run drain till at a 1-2% slope over 100 feet and it could solve my problem. but good point, i don't want to give all my education away for free but he could put in a catch basin.
also, he could build a pond, or put in several french drains running no where 2-3 wide spaced 15 feet apart or shorter depending on how bad it is, and run them straight down oh lets say 5-6 feet. or more if you want.
or he could bring in fill and raise the prop. and then have a potential law suit. and he could do many other thiings like spary it with primo or embark, ect. ect. or he could do many other things.

Drainage issues are tricky to address if we can't see them. I like the idea of bringing in contractors for options if you are uncomfortable, especially with family.

Here are a couple of general rules to follow should you decide to tackle this on your own. I invite others to add what I may be forgetting.

1. Find the source. Often water can be deverted long before it reaches the area where it is flooding. I have found several cases where a sewer drain, well out of sight, was clogged causing flooding hundreds of feet away. Get a look at this thing while it's raining. Could be someone elses problem and not your MIL's.

2. Find where the water SHOULD drain to. Everyone elses water is going somewhere. This water is probably on it's way to where it is SUPPOSED to be going; Somehow, over time, conditions have affected proper drainage and allowed it to sit. Let's get it where it goes.

3. Get it there. As others have said, there are many ways to direct water; frech drain, open ditch, etc. Whatever you choose, industry standard generally dictates that the slope of your "drain" should be 2" down for every 10' in length. So if you install and open ditch 30 feet long, it should have at least 6 inches of fall.

Combine this info with the good advice of people like Lawnstudent, Joshua and Scapasourous. Good luck.